Forum threads and product pages are full of acronyms that mean nothing until you've run into them three times. This glossary covers the 40 terms a first-week SCX24 owner actually needs to read a Hot Racing or INJORA product listing without getting lost. Plain language. No condescension.
Electronics
- 2-in-1. The combined ESC + receiver board that ships in every SCX24. Brushed-only, 5V BEC, 2S input. The first ceiling on every upgrade. See ESC/receiver combo explainer.
- BEC. Battery Eliminator Circuit. The voltage regulator inside an ESC that steps battery voltage down to 5V (or 6V/7.4V) to power the receiver and servo.
- Brushed motor. Motor with physical carbon brushes contacting a commutator. Cheap, simple, wears out. Stock SCX24 motor.
- Brushless motor. Motor with no brushes. Electronics in the ESC commutate it. Longer life, smoother, more expensive.
- ESC. Electronic Speed Controller. Drives the motor based on radio input.
- FOC. Field-Oriented Control. Sophisticated ESC firmware that does sensorless brushless almost as smoothly as sensored. What makes Furitek ESCs popular.
- Hall sensor. A small sensor inside sensored brushless motors that reports rotor position to the ESC.
- KV. Motor RPM per volt with no load. 2700KV means 2,700 RPM for every volt. Higher = faster, lower = more torque.
- LVC. Low-Voltage Cutoff. ESC behavior that cuts power when battery voltage drops too low, protecting the cells from over-discharge damage.
- PWM. Pulse-Width Modulation. How a radio signal tells a servo what angle to go to. 1500 microseconds is center.
- Receiver (RX). The radio component that listens to your transmitter.
- Sensored / sensorless. Whether a brushless motor has Hall sensors. Sensored is smoother at slow speeds.
- SLT, SLT2, SLT3. Spektrum's surface-vehicle radio protocols. Each newer version adds channels. The 2-in-1 in your SCX24 runs one of these.
- Transmitter (TX). The radio you hold.
Drivetrain
- CVD. Constant Velocity Drive. An axle shaft that delivers constant wheel speed regardless of steering angle. Upgrade from dogbones. See CVD vs. dogbones.
- Diff. Differential. Lets the wheels on one axle turn at different speeds. SCX24 uses worm-gear diffs.
- Dogbone. A one-piece axle shaft with knobs at each end that sit in cups. Cheap, fails under load. Stock SCX24 front shaft type.
- Isokinetic. A 3-section CVD design with two pivots in series. MEUS Racing's flagship axle line.
- Overdrive (OD). Wheels turn faster than the motor RPM-to-gearing ratio. Used on the front to pull through turns.
- Pinion. The small gear on the motor shaft.
- Portal axle. An axle with a gearbox at each wheel that drops the hub below the axle centerline. Adds ground clearance.
- Spur. The large gear that the pinion drives.
- Underdrive (UD). Wheels turn slower than the motor RPM-to-gearing ratio. More torque, less speed.
Chassis and suspension
- Articulation. How much one axle can rotate relative to the other (typically measured at the contact patch). More articulation = better wheel contact on uneven terrain.
- CG. Center of Gravity. The point through which gravity acts on the truck. Lower = more stable. See all about SCX24 chassis.
- LCG. Low Center of Gravity. Chassis design or modification that lowers the CG.
- Link. A rigid rod connecting the axle to the chassis. SCX24 uses a 4-link suspension.
- Pre-load. How compressed a shock spring is at full extension. Sets ride height.
- Servo saver. A spring-loaded mechanism that protects the servo from impact loads to the steering.
- Skid plate. The plate under the transmission that takes the brunt of belly-drag on obstacles.
- Spring rate. Force per millimeter of compression. Higher rate = stiffer spring.
- Tip-over angle. The side-slope angle at which the truck rolls over.
Wheels and tires
- Beadlock. A wheel design where the tire bead is mechanically clamped instead of glued. SCX24 stock wheels are beadlock.
- Compound. The rubber formulation. Softer = grippier, shorter lifespan.
- Foam (insert). The foam ring inside the tire that controls sidewall stiffness.
- Hex. The hub fitting size. SCX24 is 7mm hex.
- OD. Outer Diameter. Tire OD on SCX24 ranges 50 to 65mm.
Power
- 1S, 2S, 3S. Number of cells in series in a LiPo pack. SCX24 stock is 2S (7.4V).
- C-rating. A multiplier on capacity that tells you how fast you can pull current. 30C on a 350mAh pack = 10.5A continuous.
- LiPo. Lithium Polymer battery. The chemistry SCX24 packs use.
- mAh. Milliamp-hours. Capacity. Bigger = more runtime, more weight.
- PH 2.0. JST-PH 2.0. The white 2-pin discharge connector on SCX24 batteries.
- Storage voltage. 3.8V per cell. Where you leave LiPo packs when not driving for more than a few days.
Modifications
- Ballast. Added weight to lower CG and add traction.
- Brass. Dense metal commonly used as ballast on the axles, knuckles, and chassis.
- 4WS. Four-wheel steering. A modification that adds steering to the rear axle.
- Long travel. Suspension setup with longer-than-stock shocks for more articulation.
- LCG chassis kit. Replacement frame rails that mount lower to drop CG.
- Scale. Aesthetic prioritized over performance. Detailed bodies, accessories, realistic appearance.
Community and competition
- Comp. Competition. Timed gated courses where you drive through markers without touching them.
- Gate. A pair of markers on a comp course. Cleanly driving between them earns points; touching or missing loses points.
- RCMCCA. RC Micro Crawler Competition Association. The main org running 1/24 comp events in the US.
- RTR. Ready-To-Run. An out-of-the-box complete truck.
- Trail. Driving on natural terrain for fun, no scoring. The opposite of comp.
New term you ran into and don't see here? Most live in one of the explainer articles. Start with the learn index and search for the category.